Using experiments and combining theory and computer simulations, we show that binary complex plasmas are particularly good model systems to study the kinetics of fluid-fluid demixing at the "atomistic" (individual particle) level. The essential parameters of interparticle interactions in complex plasmas, such as the interaction range(s) and degree of nonadditivity, can be varied significantly, which allows systematic investigations of different demixing regimes. The critical role of competition between long-range and short-range interactions at the initial stage of the spinodal decomposition is discussed.

Local scaling properties of the co‐added foreground‐cleaned three‐year Wilkinson Microwave Anisotropy Probe (WMAP) data are estimated using weighted scaling indices α. The scaling index method is – for the first time – adapted and applied to the case of spherical symmetric spatial data. The results are compared with 1000 Monte Carlo simulations based on Gaussian fluctuations with a best‐fitting Λ cold dark matter power spectrum and WMAP‐like beam and noise properties. Statistical quantities based on the scaling indices, namely the mean and standard deviation, a combination of both and probability‐based measures are determined. We find for most of the test statistics highly significant deviations from the Gaussian hypothesis. Using a very conservative χ2 statistics, which averages over all scales, we detect non‐Gaussianity for the full sky at a level of 97.3 per cent regarding the mean, 97.3 per cent for the standard deviation and 97.7 per cent for a combination of mean and standard deviation. For the Northern hemisphere, the signatures of non‐Gaussianities are more pronounced and we obtain 97.7 per cent (mean), 99.8 per cent (standard deviation) and 99.0 per cent (combination), whereas the Southern hemisphere is more consistent with Gaussianity [94.8 per cent (mean), 71.0 per cent (standard deviation) and 91.5 per cent (combination)]. These differences between Northern and Southern hemispheres induce pronounced asymmetries, which can be interpreted as a global lack of structure in the Northern hemisphere, which is consistent with previous findings. Furthermore, we detect a localized anomaly in the Southern hemisphere giving rise to highly significant signature for non‐Gaussianity in the spectrum of scaling indices P(α). We identify this signature as the cold spot, which was also already detected in the first‐year WMAP data. Our results provide further evidence for both the presence of non‐Gaussianities and the presence of asymmetries in the WMAP three‐year data. More detailed band‐ and year‐wise analyses are needed to elucidate the origin of the detected anomalies. In either case the scaling indices provide powerful non‐linear statistics to analyse cosmic microwave background maps.

We study the onset and characteristics of vortices in complex (dusty) plasmas using twodimensional simulations in a setup modeled after the PK-3 Plus laboratory. A small number of microparticles initially self-arranges in a monolayer around the void. As additional particles are introduced, an extended system of vortices develops due to a non-zero curl of the plasma forces. We demonstrate a shear-thinning effect in the vortices. Velocity structure functions and the energy and enstrophy spectra show that vortex flow turbulence is present that is in essence of the "classical" Kolmogorov type.

Dedicated experiments with strongly coupled complex plasmas in external electric fields were carried out under microgravity conditions using the PK-4 dc discharge setup. The focus was put on the comparative analysis of the formation of stringlike anisotropic structures due to reciprocal (hamiltonian) and nonreciprocal (non-hamiltonian) interactions between microparticles (induced by ac and dc fields, respectively). The experiments complemented by numerical simulations demonstrate that the responses of complex plasmas in these two regimes are drastically different. It is suggested that the observed difference is a manifestation of intrinsic thermodynamic openness of driven strongly coupled systems.